Growth Directed Vertebral Fixation System With Distractible Connector(s) And Apical Control

Abstract

Growth directed correction of a spine via apical vertebral control includes securing a correction system to a first vertebra and a second vertebra of the spine, the correction system defining a correction axis extending between the first and second vertebra and securing the correction system to a third vertebra intermediate the first and second vertebra, the correction system securing the third vertebra at a fixed distance from the correction axis. The correction system is secured to the first and second vertebra such that the first and second vertebra are able to grow away from one another in a direction substantially parallel to the correction axis.

1 . (canceled) 
     
     
         2 . A spinal construct comprising:
 a first rod having a first end portion, a second end portion, and a central longitudinal axis that defines a first correction axis, the first end portion of the first rod configured to be secured to a first vertebra, the first rod having a non-circular cross-section transverse to the longitudinal axis;   a second rod having a first end portion and a second end portion, the second end portion of the second rod configured to be secured to a second vertebra,   a hosting connector assembly combining the first and second rods, the hosting connector assembly including:   a middle assembling segment having a central longitudinal axis defining a second correction axis substantially parallel to and laterally offset from the first correction axis;   a first connector having a first ring portion and a second ring portion, the first ring portion defining a first channel that receives the second end portion of the first rod to selectively lock an axial position of the first rod relative to the first connector, the second ring portion defining a second channel that receives the middle assembling segment; and   a second connector connected to the first end portion of the second rod and the middle assembling segment.   
     
     
         3 . The spinal construct of  claim 2 , wherein the first channel has a non-circular cross-section. 
     
     
         4 . The spinal construct of  claim 3 , wherein the cross-sections of the first rod and the first channel are complementary to prevent rotation of the first rod within the first channel. 
     
     
         5 . The spinal construct of  claim 4 , wherein the second channel has a non-circular cross-section. 
     
     
         6 . The spinal construct of  claim 5 , wherein the cross-sections of the middle assembling segment and the second channel are complementary to prevent rotation of the middle assembling segment within the second channel. 
     
     
         7 . The spinal construct of  claim 2 , wherein the middle assembling segment has a non-circular cross-section, the cross-section being transverse to the central longitudinal axis of the middle assembling segment. 
     
     
         8 . The spinal construct of  claim 7 , wherein the middle assembling segment is symmetric about a plane extending along the central longitudinal axis of the middle assembling segment. 
     
     
         9 . The spinal construct of  claim 2 , wherein the non-circular cross-section of the first rod is formed by a first chase feature to prevent rotation of the first within the first channel. 
     
     
         10 . The spinal construct of  claim 9 , wherein the first channel has a non-circular cross-section formed by a second chase feature positioned on an inner surface of the first ring portion and projecting inward into the first channel. 
     
     
         11 . The spinal construct of  claim 10 , wherein the first chase feature of the first rod includes a groove to receive the second chase feature. 
     
     
         12 . The spinal construct of  claim 2 , wherein the first rod has a square-shaped cross-section. 
     
     
         13 . The spinal construct of  claim 2 , wherein the first rod is symmetric about a plane extending along the central longitudinal axis of the first rod. 
     
     
         14 . The spinal construct according to  claim 2 , wherein the second rod is coaxial with the first rod. 
     
     
         15 . The spinal construct according to  claim 2 , further comprising an intermediate connector secured to the middle assembling segment and extending in a substantially transverse direction away from the first and second correction axes of the system, the intermediate connector configured to be secured to a third vertebra located between the first and second vertebrae to selectively lock a distance between the third vertebra and the second correction axis. 
     
     
         16 . A spinal construct comprising:
 a first rod;   a second rod; and   a hosting connector assembly for combining first and second coaxial rods, the hosting connector assembly comprising:   a middle assembling segment having a central longitudinal axis defining a first axis;   a first connector having a first ring and a second ring of monolithic construction with one another, the first ring defining a first channel about a second axis parallel to and laterally offset from the first axis, the first channel configured to receive the first rod to selectively lock an axial position of the first rod relative to the first connector, the second ring defining a channel that receives the middle assembling segment; and   a second connector connected to the middle assembling segment and configured to receive the second rod coaxially disposed about the second axis, the second connector being spaced apart longitudinally from the first connector,   wherein at least one of the first rod and the middle assembling segment has a non-circular cross-section.   
     
     
         17 . The spinal construct of  claim 16 , wherein the second rod is coaxial with the first rod. 
     
     
         18 . The spinal construct of  claim 16 , wherein the first rod and the first channel each have a non-circular cross-section, the cross-sections of the first rod and the first channel are complementary to prevent rotation of the first rod within the first channel. 
     
     
         19 . The spinal construct of  claim 18 , wherein the middle assembling segment and the second channel each have a non-circular cross-section, the sections of the middle assembling segment and the second channel are complementary to prevent rotation of the middle assembling segment within the second channel. 
     
     
         20 . A spinal construct comprising:
 a first rod;   a second rod; and   a hosting connector assembly for combining first and second coaxial rods, the hosting connector assembly comprising:   a middle assembling segment having a central longitudinal axis defining a first axis;   a first connector having a first ring and a second ring of monolithic construction with one another, the first ring defining a first channel about a second axis parallel to and laterally offset from the first axis, the first channel configured to receive the first rod to selectively lock an axial position of the first rod relative to the first connector, the second ring defining a channel that receives the middle assembling segment; and   a second connector connected to the middle assembling segment and configured to receive the second rod coaxially disposed about the second axis, the second connector being spaced apart longitudinally from the first connector,   wherein the first rod and middle assembling segment are prevented from rotating with respect to each other.